In recent years, with the increased broadband penetration as well as digital broadcasting for example, home networking has been expanding to involve not only a PC (Personal Computer) but also home electrical devices.
Japanese Patent Laying-Open No. 2001-145140 (Patent Document 1) discloses a program recording system. The program recording system enables a user to know programs and make a program recording reservation even away from home by means of a wireless telephone. For example, a user can know what programs are to be broadcasted, through program guide information provided from a recording reservation site to a portable terminal. Further, in response to a user's designation of a program, information about a reservation for the program is transmitted from the recording reservation site to the portable terminal. Based on the information about the reservation, the user can make a recording reservation at a recording apparatus such as video tape recorder.
Japanese Patent Laying-Open No. 2005-236890 (Patent Document 2) discloses a portable terminal having the capability of recording a video audio signal. The portable terminal can inform a user of the conditions of the terminal itself before recording a video audio signal based on information about a reservation. For example, the terminal calculates the conditions of the terminal itself such as the free space of the recording area and the remaining capacity of the battery. If the space/capacity is insufficient, the user is notified of the shortage in space/capacity. Accordingly, the user can take necessary measures in advance.
Japanese Patent Laying-Open No. 2002-204475 (Patent Document 3) discloses a telephone subscriber management apparatus. With the subscriber management apparatus, a user of a portable terminal can know that there is an incoming call even when the incoming call arrives in the state where the portable terminal cannot make communication. For example, in the case where a receiver terminal cannot receive an incoming call because the terminal is out of the service area for example, the subscriber management apparatus stores the incoming call. When the subscriber management apparatus finds that the receiver terminal becomes able to make a call, the apparatus notifies the receiver terminal of the stored incoming call.    Patent Document 1: Japanese Patent Laying-Open No. 2001-145140    Patent Document 2: Japanese Patent Laying-Open No. 2005-236890    Patent Document 3: Japanese Patent Laying-Open No. 2002-204475